JPH09118871A - Organopolysiloxane for silicone pressure-sensitive adhesive and silicone pressure-sensitive adhesive - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a silicone pressure-sensitive adhesive which can well bond to silicone rubber by curing through an addition reaction and an organopolysiloxane for preparing the adhesive. SOLUTION: This silicone pressure-sensitive adhesive comprises (A) an organopolysiloxane prepared by partial condensation reaction between (a) a crude rubber-like diorganopolysiloxane of which 10-80 mole % of molecular chain terminal groups are an alkenyl group and the rest are hydroxy groups bonding to silicone atoms and (b) an organopolysiloxane containing one or more hydroxy or alkoxy groups to silicon atoms on the average represented by the average unit formula of (R<1> 3 SiO1/2 )X(SiO4/2 )1.0 (where R<1> is a hydrocarbon group; (x) is 0.5-1.0) by using (c) an amine boiling at -10-+200 deg.C under normal pressure, (B) an organopolysiloxane containing 2 or more hydrogen atoms bonding to silicone atoms on the average and (C) a platinum catalyst.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organopolysiloxane for silicone-based pressure-sensitive adhesives and a silicone-based pressure-sensitive adhesive. More specifically, it is a silicone-based pressure-sensitive adhesive that cures by an addition reaction and adheres well to silicone rubber. It relates to adhesives and organopolysiloxanes for preparing them.

[0002]

2. Description of the Related Art Silicone pressure-sensitive adhesives are used as highly reliable pressure-sensitive adhesives because of their excellent properties such as electrical insulation, cold resistance and tackiness. This silicone-based pressure-sensitive adhesive is classified into, for example, an addition reaction-curing type, a condensation reaction-curing type, and a peroxide-curing type according to this curing mechanism. Since it cures rapidly at room temperature or by heating, Silicone pressure sensitive adhesives are preferably used. Examples of the addition reaction-curable silicone pressure-sensitive adhesive include, for example, an organopolysiloxane composed of a monofunctional siloxane unit and a tetrafunctional siloxane unit, a diorganopolysiloxane whose both molecular chain ends are blocked with vinyl groups, A silicone-based pressure-sensitive adhesive comprising an organopolysiloxane containing an average of two or more silicon-bonded hydrogen atoms in one molecule, and a platinum-based catalyst (see Japanese Patent Publication No. 54-37907), and silicon at both ends of the molecular chain. A diorganopolysiloxane blocked with an atom-bonded hydroxyl group and an organopolysiloxane partially condensed with an organopolysiloxane composed of a monofunctional siloxane unit and a tetrafunctional siloxane unit, an organopolysiloxane containing a silicon atom-bonded hydrogen atom, Silicone pressure-sensitive adhesive consisting of platinum catalyst 5
No. 34391), a diorganopolysiloxane in which both ends of the molecular chain are blocked with alkenyl groups, an organopolysiloxane composed of a monofunctional siloxane unit and a tetrafunctional siloxane unit, and 2 or more on average in one molecule. An organopolysiloxane containing silicon-bonded hydrogen atoms,
A silicone-based pressure-sensitive adhesive composed of a platinum-based catalyst and an organic solvent (see JP-A-63-22886) is known.

In particular, a diorganopolysiloxane having both ends of its molecular chain blocked with a hydroxyl group bonded to a silicon atom and an organopolysiloxane partially condensed with an organopolysiloxane composed of a monofunctional siloxane unit and a tetrafunctional siloxane unit are blended. By doing so, stable tackiness can be imparted to the silicone-based pressure-sensitive adhesive. As a method for partially condensing a diorganopolysiloxane having both ends of its molecular chain blocked by a hydroxyl group bonded to a silicon atom and an organopolysiloxane composed of a monofunctional siloxane unit and a tetrafunctional siloxane unit, heating these to a high temperature And partial condensation with ammonia (see Japanese Patent Publication No. 6-94553).

[0004]

However, even an addition reaction-curable silicone-based pressure-sensitive adhesive compounded with the organopolysiloxane prepared in this manner has a problem that the adhesiveness to silicone rubber is poor. It was
The present inventors have arrived at the present invention as a result of intensive studies on the above problems. That is, it is an object of the present invention to provide a silicone-based pressure-sensitive adhesive which is cured by an addition reaction and sticks well to silicone rubber, and an organopolysiloxane for preparing the same.

[0005]

Means for Solving the Problem and Its Action The organopolysiloxane for silicone-based pressure-sensitive adhesives of the present invention comprises:
(a) A raw rubber-like diorganopolysiloxane in which 10 to 80 mol% of the molecular chain end groups are alkenyl groups and the rest are hydroxyl groups bonded to silicon atoms, and (b) one or more silicon atoms on average in the molecule. An average unit formula containing a hydroxyl group or an alkoxy group bonded to: (R ¹ ₃ SiO _1/2 ) _x (SiO _4/2 ) _1.0 (wherein R ¹ is a substituted or unsubstituted monovalent hydrocarbon group) And x is a number of 0.5 to 1.0), and (c) has a boiling point of −10 under normal pressure.
It is characterized by being partially condensed with an amine compound having a temperature of up to 200 ° C. The silicone-based pressure-sensitive adhesive of the present invention contains (A) the organopolysiloxane for a silicone-based pressure-sensitive adhesive described above, and (B) an average of two or more silicon atom-bonded hydrogen atoms in one molecule. An organopolysiloxane (amount that donates 0.7 mol or more of silicon atom-bonded hydrogen atoms to 1 mol of alkenyl group in component (A)), and
(C) Platinum-based catalyst {The platinum metal in the component (C) is less than 0.1% by weight relative to the organopolysiloxane component in the composition.
1 to 1000 ppm}.

First, the organopolysiloxane for silicone pressure-sensitive adhesives of the present invention will be described in detail. The component (a) is a gum-like diorganopolysiloxane in which 10 to 80 mol% of the molecular chain terminal groups are alkenyl groups and the rest are hydroxyl groups bonded to silicon atoms. This is because when diorganopolysiloxane having less than 10 mol% of the end of the molecular chain is an alkenyl group and the rest is a hydroxyl group bonded to a silicon atom, partial condensation between the diorganopolysiloxane occurs, This is because it is not possible to prepare a silicone-based pressure-sensitive adhesive that adheres well to silicone rubber, and diorgano in which less than 20 mol% of the end of the molecular chain is a hydroxyl group bonded to a silicon atom and the rest is an alkenyl group. This is because when polysiloxane is used, it is less likely to partially condense with the component (b). Although the component (a) is substantially linear, it may have some branches in its molecular chain. Examples of the group bonded to the side chain of the molecular chain in the component (a) include an alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, and a heptyl group; a vinyl group, an allyl group, a butenyl group, Alkenyl groups such as pentenyl group; aryl groups such as phenyl group, tolyl group, xylyl group; aralkyl groups such as benzyl group, phenethyl group; chloromethyl group, 3-chloropropyl group, 3,3,3-trifluoropropyl group Examples thereof include monovalent hydrocarbon groups such as halogenated alkyl groups, such as methyl group, vinyl group and phenyl group. The component (a) is in the form of raw rubber, but in particular, its plasticity (William plasticity measured according to the method specified in JIS K 6300: 25 ° C., after 3 minutes)
Is preferably in the range of 100-160.

The component (b) contains an average unit formula of (R ¹ ₃ SiO _1/2 ) _x (SiO _4/2 ) containing a hydroxyl group or an alkoxy group bonded to one or more silicon atoms on average in the molecule. It is an organopolysiloxane represented by _1.0 . In the above formula, R
¹ is a substituted or unsubstituted monovalent hydrocarbon group, and examples thereof include the same monovalent hydrocarbon groups as described above. The component (b) contains an average of at least one hydroxyl group or alkoxy group bonded to a silicon atom in the molecule, because it is partially condensed with the component (a). The content of the hydroxyl group or the alkoxy group bonded to the silicon atom in the component (b) is 1
It is preferably 0% by weight or less, and particularly preferably 5% by weight or less. Examples of the alkoxy group bonded to the silicon atom in the component (b) include a methoxy group, an ethoxy group and a propoxy group. Also, in the above formula,
x is a monofunctional siloxane unit (ie, R ¹ ₃ ) with respect to a tetrafunctional siloxane unit (ie, SiO _4/2 unit).
It is a number in the range of 0.5 to 1.0 and preferably in the range of 0.6 to 0.9, which represents the molar ratio of (SiO _1/2 unit). This is because the silicone-based pressure-sensitive adhesive containing the organopolysiloxane in which x is less than 0.5 has poor tackiness, and the organopolysiloxane in which the number is more than 1.0 is mixed. This is because the silicone pressure-sensitive adhesive has poor cohesive strength.

When the component (a) and the component (b) are partially condensed,
As the blending amount of these components, the weight of the component (a): the weight of the component (b) is preferably 2: 8 to 8: 2, and particularly preferably 3: 7 to 7: 3.

The amine compound as the component (c) is a condensation reaction catalyst for partially condensing the above components (a) and (b), and has a boiling point within the range of -10 to 200 ° C under normal pressure. Yes, it is preferably in the range of −10 to 150 ° C., and more preferably in the range of 30 to 100 ° C. This is because when an amine compound having a boiling point under atmospheric pressure lower than −10 ° C. is used as a condensation reaction catalyst, partial condensation of the components (a) and (b) does not easily proceed, and the amine which exceeds 200 ° C. This is because the silicone-based pressure-sensitive adhesive containing the organopolysiloxane obtained by using the compound has poor cohesive strength. Examples of the component (c) include methylamine (bp = −9.7 ° C.) and ethylamine (bp).
= 16.6), n-propylamine (bp = 49)
C.), i-propylamine (bp = 32 ° C.), n-
Butylamine (bp = 78 ° C.), amylamine (bp = 104 ° C.), n-heptylamine (b.p. = 104 ° C.)
p. = 155 ° C.) and other aliphatic primary amine compounds; dimethylamine (bp = 7.4 ° C.), diethylamine (bp = 55.5 ° C.), di-n-propylamine (bp). = 110 ° C), di-i-propylamine (bp = 84 ° C), di-n-butylamine (b.p.
p. = 159 ° C) and other aliphatic secondary amine compounds; trimethylamine (bp = 3.2 to 3.8 ° C), triethylamine (bp = 89.4 ° C), tri-n-propylamine ( bp = 156.5 ° C.) and other aliphatic tertiary amine compounds; allylamine (bp = 58 ° C.) and other aliphatic unsaturated amine compounds; cyclopropylamine (b.p.
p. = 50 ° C.), cyclobutylamine (bp = 82)
C.), cyclopentylamine (bp = 107-10)
8 ° C.), cyclohexylamine (bp = 134 ° C.)
Alicyclic amine compounds such as aniline (bp = 184)
C.), methylaniline (bp = 196.1 ° C.), dimethylaniline (bp = 193 ° C.), benzylamine (bp = 185 ° C.), and other aromatic amine compounds.

The amount of the component (c) to be blended is as follows:
0.001 to 1 per 100 parts by weight of the total amount of the component (b)
It is preferably in the range of 0 part by weight, and particularly preferably in the range of 0.01 to 1 part by weight.

The method for producing the organopolysiloxane for silicone-based pressure-sensitive adhesives of the present invention is as follows.
Generally, the components and the component (b) are uniformly mixed in an organic solvent, if necessary, and then the component (c) is added to this system to partially condense. The blending of this organic solvent is optional,
By using the organic solvent, the partial condensation of the component (a) and the component (b) can be rapidly advanced. As the organic solvent, the component (a) and the component (b) can be compatibilized, and
Any solvent that does not inhibit the partial condensation of the components (a) and (b) may be used, and examples thereof include aromatic solvents such as toluene and xylene; aliphatic solvents such as hexane and heptane; acetone;
Examples thereof include ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone, and aromatic solvents such as toluene and xylene are particularly preferable. Further, although this partial condensation proceeds even at room temperature, in order to carry out this partial condensation rapidly, it is preferable to heat this system to such an extent that the component (c) does not evaporate. It is preferable to heat to ˜70 ° C. Further, the progress of partial condensation can be confirmed by the infrared spectroscopic analysis or ²⁹ Si-nuclear magnetic resonance spectroscopic analysis of the reaction product from this system, by the decrease of the hydroxyl group or alkoxy group bonded to the silicon atom. Further, the progress of this partial condensation can be easily confirmed by the fact that the viscosity of this system increases. After partially condensing the components (a) and (b),
It is preferable to distill off the component (c) by heating this system. In order to distill off the component (c) from this system, the system is heated to a temperature higher than the boiling point of the component (c), the system is depressurized, and nitrogen gas, helium gas, and argon are added to the system. It may be distilled off together with this inert gas through an inert gas such as gas.

Such an organopolysiloxane for a silicone-based pressure-sensitive adhesive of the present invention has the above-mentioned components (a) and (b).
Although the components are partially condensed, the unreacted component (a) which is not partially condensed in the organopolysiloxane and
It may contain the component (b). The organopolysiloxane may contain the organic solvent used in the partial condensation.

Next, the silicone pressure-sensitive adhesive of the present invention will be described in detail. The component (A) is the main component of the present composition, and as described above, it is the organopolysiloxane for a silicone pressure-sensitive adhesive obtained by partially condensing the components (a) and (b) with the component (c). The component (A) may be used as the organic solution used when preparing this.

The component (B) is a crosslinking agent of the present composition, and is an organopolysiloxane containing an average of two or more silicon atom-bonded hydrogen atoms in one molecule. The bonding position of the silicon atom-bonded hydrogen atom in the component (B) includes, for example, a molecular chain terminal and / or a molecular chain side chain. (B)
Examples of the group bonded to the silicon atom in the component include an alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, and a heptyl group; a phenyl group, a tolyl group, a xylyl group, and a naphthyl group. And aryl groups such as benzyl group and phenethyl group; monovalent hydrocarbon groups such as halogenated alkyl groups such as chloromethyl group, 3-chloropropyl group and 3,3,3-trifluoropropyl group. In particular, a methyl group and a phenyl group are preferable. Examples of the molecular structure of the component (B) include straight-chain, branched, cyclic, network, and partially branched straight-chain structures, and the straight-chain structure is particularly preferable. The viscosity of the component (B) at 25 ° C. is 1
It is preferably in the range of to 500,000 centipoise, and particularly preferably in the range of 5 to 100,000 centipoise.

Examples of the organopolysiloxane of the component (B) include, for example, methylhydrogenpolysiloxane endcapped with trimethylsiloxy groups at both ends of the molecular chain and dimethylsiloxane endcapped with trimethylsiloxy groups at both ends of the molecular chain.
Methyl hydrogen siloxane copolymer, dimethylsiloxy group-capped dimethylsiloxysiloxane / methylphenylsiloxane copolymer, both ends of molecular chain dimethylpolysiloxane, dimethylhydrogensiloxy group dimethylpolysiloxane, both ends of molecular chain Hydrogensiloxy group-capped dimethylsiloxane / methylphenylsiloxane copolymer, molecular chain both terminals dimethylhydrogensiloxy group-blocked methylphenylpolysiloxane, siloxane unit represented by formula: R ² ₃ SiO _1/2 and formula: R ² ₂ An organopolysiloxane copolymer comprising a siloxane unit represented by HSiO _1/2 and a siloxane unit represented by the formula: SiO _4/2 , a siloxane unit represented by R ² ₂ HSiO _1/2 and a formula: SiO _4/2 From the siloxane units shown Organopolysiloxane copolymers, wherein: the siloxane units represented by the formula R ² HSiO _2/2: siloxane unit or expression represented by R ² SiO _3/2:
Examples thereof include organopolysiloxane copolymers composed of siloxane units represented by HSiO _3/2 , and mixtures of two or more of these organopolysiloxanes. In the above formula, R ² is a monovalent hydrocarbon group other than an alkenyl group,
For example, methyl group, ethyl group, propyl group, butyl group,
Alkyl group such as pentyl group, hexyl group and heptyl group;
Aryl groups such as phenyl group, tolyl group, xylyl group and naphthyl group; aralkyl groups such as benzyl group and phenethyl group; chloromethyl group, 3-chloropropyl group, 3,3,3
Examples thereof include halogenated alkyl groups such as 3-trifluoropropyl group.

The blending amount of the component (B) is an amount that donates 0.7 mol or more of silicon atom-bonded hydrogen atoms to 1 mol of the alkenyl group in the component (A). In practice, the upper limit is 10 mol.
It is preferably 0 or less. This is an amount such that the silicon atom-bonded hydrogen atoms in the component (B) are less than 0.7 mol per 1 mol of the alkenyl group in the component (A). The silicone pressure-sensitive adhesive is sufficiently cured. This is because it does not.

The platinum-based catalyst of the component (C) is a catalyst for curing the composition by promoting the addition reaction between the alkenyl group in the component (A) and the silicon atom-bonded hydrogen atom in the component (B). Is. Examples of the component (C) include platinum fine powder, platinum black, platinum-supported silica fine powder, platinum-supported activated carbon,
Examples thereof include chloroplatinic acid, platinum tetrachloride, alcohol solutions of chloroplatinic acid, platinum-olefin complexes, and platinum-alkenylsiloxane complexes such as divinyltetramethyldisiloxane.

The blending amount of the component (C) is such that the platinum metal in the component (C) is 0.1 to 1000 ppm by weight with respect to the organopolysiloxane component in the composition.
In particular, the amount is preferably 1 to 500 ppm. This is because the platinum metal in the component (C) is 0.1 p by weight unit with respect to the organopolysiloxane component in the composition.
This is because the silicone-based pressure-sensitive adhesive having a viscosity of less than pm is extremely slow in curing, and the silicone-based pressure-sensitive adhesive having a viscosity of more than 1000 ppm is colored.

The silicone-based pressure-sensitive adhesive of the present invention, as described above
The component (A) to the component (C), but as other optional components, for example, organic solvents such as toluene, xylene, hexane, heptane, acetone, methyl ethyl ketone, methyl isobutyl ketone; tetramethoxysilane, tetraethoxysilane, dimethyl. Dimethoxysilane, methylphenyldimethoxysilane, methylphenyldiethoxysilane, phenyltrimethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, allyltrimethoxysilane, allyltriethoxysilane, 3-glycidoxypropyl Alkoxysilane compounds such as trimethoxysilane and 3-methacryloxypropyltrimethoxysilane; 3-methyl-1-butyn-3-ol, 3,5-dimethyl-1-hexyne-3-
All, 3-methyl-1-penten-3-ol, 3-
Alkyne alcohols such as phenyl-1-butyn-3-ol, 3-methyl-3-penten-1-yne, 3,5-
Enyne compounds such as dimethyl-3-hexene-1-yne; 1,3,5,7-tetramethyl-1,3,5,7-
Tetravinylcyclotetrasiloxane, 1,3,5,7
-Tetramethyl-1,3,5,7-tetrahexenylcyclotetrasiloxane, a curing inhibitor such as benzotriazole; an inorganic filler such as fumed silica, precipitable silica, titanium dioxide, carbon black, alumina and quartz powder; And a filler obtained by surface-treating these inorganic fillers with an organosilicon compound such as organoalkoxysilane, organochlorosilane, or organosilazane;
Antioxidants, pigments, stabilizers can be mentioned.

Such a silicone-based pressure-sensitive adhesive is coated on a release paper, cured, and then pressure-bonded to a support to prepare an adhesive material. A pressure-sensitive adhesive can be applied onto a support and cured to form an adhesive. Examples of the support include plastic films such as polyester resin such as polyethylene terephthalate resin and polyimide resin; paper such as Japanese paper and synthetic paper, cloth, glass wool,
Examples include metal foil. Also, as this release paper, plastic films whose both sides or one side is release-treated,
Examples include papers. Also, as this shape, for example,
Examples include tape-shaped, film-shaped, and sheet-shaped.

[0021]

EXAMPLES The organopolysiloxane for silicone-based pressure-sensitive adhesives and the silicone-based pressure-sensitive adhesives of the present invention will be described in detail with reference to Examples. The viscosity in the examples is 25 ° C.
The value of the silicone pressure-sensitive adhesive was measured as follows.

[Adhesiveness] 30 μm of a silicone pressure-sensitive adhesive is applied on a support made of polyethylene terephthalate resin.
After coating to a thickness of about m, this was heated at 100 ° C. for 3 minutes to prepare an adhesive sheet. Next, this adhesive sheet was cut into a width of 2.5 cm to prepare an adhesive tape. 2Kg of this adhesive tape on an adherend made of stainless steel plate (SUS304) polished with No. 280 waterproof paper
The rubber roller of f was used for pressure bonding. Then, it is left at room temperature for 30 minutes, and it is moved at a constant speed (300 mm / mi).
This adhesive force was measured by the 180-degree peeling method using the tensile tester of n). The adhesive strength was measured in the same manner as above except that a silicone rubber sheet was used as the adherend.

[Tack (ball rolling method)] A silicone pressure-sensitive adhesive is applied on a support made of polyethylene terephthalate resin to a thickness of about 30 μm, and then this is applied at 100 ° C.
It was heated for 3 minutes to prepare an adhesive sheet. The tack of this pressure-sensitive adhesive sheet was measured according to the test method specified in JIS Z 0237. That is, the adhesive surface of this adhesive sheet was attached to the inclined plate, and the angle of the inclined plate was 30 °. A 100 mm long runway is provided at the upper end of this inclined plate, and a steel ball is rolled from this runway to
The ball number of the steel ball stopping at the position of 00 mm was obtained.

[Peeling resistance] A silicone-based pressure-sensitive adhesive of 30 μm is applied to a release film made of polyethylene terephthalate resin whose surface is treated with fluorosilicone resin
After coating to a front and back thickness, this was heated at 100 ° C. for 3 minutes. Next, a polyethylene terephthalate resin film was attached to this adhesive surface and left at room temperature for 30 minutes while applying a load of 20 gf / cm ² . This was cut into a width of 2.5 cm to prepare an adhesive tape. The peeling resistance of this adhesive tape was measured by a 180-degree peeling method using a constant speed (300 mm / min) tensile tester. In addition, the adhesive tape whose peel resistance was measured is 2
The adherend made of a stainless steel plate (SUS304) polished with No. 80 water resistant polishing paper was pressure-bonded using a 2 Kgf rubber roller. Then, the mixture was allowed to stand at room temperature for 30 minutes, and the adhesive force after the peel resistance test was measured by a 180 ° peeling method using a constant speed (300 mm / min) tensile tester.

[Example 1] 20 mol% of the end groups of the molecular chain are vinyl groups, the rest are hydroxyl groups bonded to silicon atoms, and the degree of plasticity is 142. A raw rubber-like dimethylpolysiloxane (containing vinyl groups) Amount = 0.004% by weight) 27
Parts by weight and average unit formula: [(CH ₃ ) ₃ SiO _1/2 ] _0.7 (SiO _4/2 ) _1.0 represented by organopolysiloxane (containing 2.0% by weight of a hydroxyl group bonded to a silicon atom). 35 parts by weight were uniformly mixed with 40 parts by weight of xylene, and then 0.3 part by weight of n-butylamine (bp = 78 ° C.) was added to this system. The system was heated to 70 ° C. and stirred for 1 hour. After confirming that the partial condensation proceeded, the mixture was heated and stirred at 140 ° C. for 2 hours while flowing nitrogen gas into the system to distill off n-butylamine. Then, xylene was added to this system so that the content of the organopolysiloxane component was 60% by weight to prepare a xylene solution of 350 poises of the organopolysiloxane for a silicone pressure-sensitive adhesive. Next, 20 parts by weight of 100 parts by weight of this xylene solution of the organopolysiloxane for silicone pressure sensitive adhesives is used.
0.2 parts by weight of centipoise molecular chain end-capped trimethylsiloxy group-blocked methylhydrogenpolysiloxane (content of hydrogen atoms bonded to silicon atom = 1.56% by weight), 3
-Methyl-1-butyn-3-ol (0.2 parts by weight) and toluene (50 parts by weight) were mixed, and platinum 1,
The organodipoly (3-divinyl-1,1,3,3-tetramethyldisiloxane) complex was added in an amount such that the platinum metal in the complex was 100 ppm by weight with respect to the organopolysiloxane component. 40 siloxane components
A weight percent silicone pressure sensitive adhesive was prepared. Various properties of this pressure-sensitive adhesive were measured by the above methods, and the results are shown in Table 1.

Example 2 A raw rubber-like dimethylpolysiloxane having a plasticity of 140, in which 25 mol% of the molecular chain end groups are vinyl groups and the rest are hydroxyl groups bonded to silicon atoms (containing vinyl groups). Amount = 0.005% by weight) 27
Parts by weight and average unit formula: [(CH ₃ ) ₃ SiO _1/2 ] _0.8 (SiO _4/2 ) _1.0 represented by organopolysiloxane (containing 2.0% by weight of a hydroxyl group bonded to a silicon atom). 35 parts by weight and 40 parts by weight of xylene were uniformly mixed, and then 0.3 part by weight of triethylamine (bp = 89.4 ° C.) was added to the system. The system was heated to 70 ° C. and stirred for 1 hour. After confirming that the partial condensation proceeded, the mixture was heated and stirred at 140 ° C. for 2 hours while flowing nitrogen gas into the system to distill off triethylamine. Then, xylene was added to this system to make the organopolysiloxane component 60%.
A xylene solution of organopolysiloxane for silicone pressure-sensitive adhesive having a weight percentage of 780 poise was prepared. Next, in 100 parts by weight of a xylene solution of this organopolysiloxane for a silicone-based pressure-sensitive adhesive, a 20-centipoise molecular chain end-capped trimethylsiloxy group-blocked methylhydrogenpolysiloxane (content of silicon-bonded hydrogen atoms = 1.56) % By weight), 0.2 parts by weight of 3-methyl-1-butyn-3-ol, and 50 parts by weight of toluene are mixed, and then 1,3-divinyl-1,1, platinum. The complex of 3,3-tetramethyldisiloxane is added in an amount such that the platinum metal in the complex is 150 ppm by weight unit with respect to the organopolysiloxane component, and the organopolysiloxane component is 40% by weight. A silicone-based pressure sensitive adhesive was prepared. Various properties of this pressure-sensitive adhesive were measured by the above methods, and the results are shown in Table 1.

Example 3 A raw rubber-like dimethylpolysiloxane having a plasticity of 138 in which 60 mol% of the end groups of the molecular chain are vinyl groups and the rest are hydroxyl groups bonded to silicon atoms (containing vinyl groups) Amount = 0.01% by weight) 27 parts by weight and an average unit formula: [(CH ₃ ) ₃ SiO _1/2 ] _0.7 (SiO _4/2 ) _1.0 Organopolysiloxane represented by (a hydroxyl group bonded to a silicon atom 35 parts by weight are uniformly mixed with 40 parts by weight of xylene, and then 0.3 part by weight of n-propylamine (bp = 49 ° C.) is added to the system. . The system was heated to 70 ° C. and stirred for 1 hour. After confirming that the partial condensation proceeded, the mixture was heated and stirred at 140 ° C. for 2 hours while flowing nitrogen gas into the system to distill off n-propylamine. Then, xylene was added to this system to make the organopolysiloxane component 60%.
A xylene solution of a silicone-based organopolysiloxane for pressure-sensitive adhesives having a porosity of 440 poise was prepared. Next, in 100 parts by weight of a xylene solution of this organopolysiloxane for a silicone-based pressure-sensitive adhesive, 20 centipoise of both ends of a molecular chain, a trimethylsiloxy group-blocked methylhydrogenpolysiloxane (content of silicon-bonded hydrogen atoms = 1.56 % By weight), 0.2 parts by weight of 3-methyl-1-butyn-3-ol, and 50 parts by weight of toluene are mixed, and then 1,3-divinyl-1,1, platinum. The complex of 3,3-tetramethyldisiloxane is added in an amount such that the platinum metal in the complex is 300 ppm by weight with respect to the organopolysiloxane component, and the organopolysiloxane component is 40% by weight. A silicone-based pressure sensitive adhesive was prepared. Various properties of this pressure-sensitive adhesive were measured by the above methods, and the results are shown in Table 1.

Example 4 Crude rubber-like dimethylsiloxane / methylvinylsiloxane / methyl having a plasticity of 154 in which 20 mol% of the terminal groups of the molecular chain are vinyl groups and the rest are hydroxyl groups bonded to silicon atoms. Phenylsiloxane copolymer (96 mol% of the groups on the side chains of the molecular chain are methyl groups, 0.5 mol% are vinyl groups, 3.5 mol%
Is a phenyl group. Content of vinyl group = 0.007% by weight) 27 parts by weight and average unit formula: [(CH ₃ ) ₃ SiO _1/2 ] _0.7 (SiO _4/2 ) _1.0 Organopolysiloxane represented by 2.0 parts by weight of a hydroxyl group to be bonded is contained.) 35 parts by weight are uniformly mixed with 40 parts by weight of xylene, and then 0.3 part by weight of n-butylamine (bp = 78 ° C.) is added to this system. Added in parts. The system was heated to 70 ° C. and stirred for 1 hour. After confirming that the partial condensation proceeded, the mixture was heated and stirred at 140 ° C. for 2 hours while flowing nitrogen gas into the system to distill off n-butylamine. Then, toluene was added to this system to make the organopolysiloxane component 60% by weight to prepare a xylene solution of a silicone-based organopolysiloxane for a pressure-sensitive adhesive of 350 poise. Next, in 100 parts by weight of a xylene solution of this organopolysiloxane for a silicone-based pressure-sensitive adhesive, 20 centipoise of both ends of a molecular chain, a trimethylsiloxy group-blocked methylhydrogenpolysiloxane (content of silicon-bonded hydrogen atoms = 1.56) was added. % By weight), 0.2 parts by weight of 3-methyl-1-butyn-3-ol, and 50 parts by weight of toluene are mixed, and then 1,3-divinyl-1,1, platinum. The complex of 3,3-tetramethyldisiloxane is added in an amount such that the platinum metal in the complex is 100 ppm by weight unit with respect to the organopolysiloxane component, and the organopolysiloxane component is 40% by weight. A silicone-based pressure sensitive adhesive was prepared. Various properties of this pressure-sensitive adhesive were measured by the above methods, and the results are shown in Table 1.

[Comparative Example 1] A raw rubber-like dimethylpolysiloxane having a plasticity of 142, in which 20 mol% of the terminal groups of the molecular chain are vinyl groups and the rest are hydroxyl groups bonded to silicon atoms (containing vinyl groups). Amount = 0.004% by weight) 27
Parts by weight and average unit formula: [(CH ₃ ) ₃ SiO _1/2 ] _0.7 (SiO _4/2 ) _1.0 represented by organopolysiloxane (containing 2.0% by weight of a hydroxyl group bonded to a silicon atom). 35 parts by weight were uniformly mixed with 40 parts by weight of xylene, and then 1.2 parts by weight of 29% by weight aqueous ammonia solution was added to this system. The system was heated to 70 ° C. and stirred for 1 hour. After confirming that the partial condensation proceeded, the mixture was heated and stirred at 140 ° C. for 2 hours while flowing nitrogen gas into the system to vaporize ammonia. Then, xylene was added to this system to make the organopolysiloxane component 60% by weight,
A xylene solution of organopolysiloxane for silicone pressure sensitive adhesive having a poise of 410 was prepared. Next, in 100 parts by weight of a xylene solution of this organopolysiloxane for a silicone-based pressure-sensitive adhesive, a 20-centipoise molecular chain end-capped trimethylsiloxy group-blocked methylhydrogenpolysiloxane (content of hydrogen atoms bonded to silicon atom = 1.
56% by weight) 0.2 parts by weight, 3-methyl-1-butyne-
After 0.2 parts by weight of 3-ol and 50 parts by weight of toluene were mixed, platinum 1,3-divinyl-1,1, was added thereto.
The complex of 3,3-tetramethyldisiloxane is added in an amount such that the platinum metal in the complex is 100 ppm by weight unit with respect to the organopolysiloxane component, and the organopolysiloxane component is 40% by weight. A silicone-based pressure sensitive adhesive was prepared. Various properties of this pressure-sensitive adhesive were measured by the above methods, and the results are shown in Table 1.

Comparative Example 2 Crude rubber-like dimethylpolysiloxane having a plasticity of 142, in which 20 mol% of the terminal groups of the molecular chain are vinyl groups and the rest are hydroxyl groups bonded to silicon atoms (containing vinyl groups). Amount = 0.004% by weight) 27
Parts by weight and average unit formula: [(CH ₃ ) ₃ SiO _1/2 ] _0.7 (SiO _4/2 ) _1.0 represented by organopolysiloxane (containing 2.0% by weight of a hydroxyl group bonded to a silicon atom). 35 parts by weight of 40 parts by weight of xylene were uniformly mixed, and the system was stirred at 70 ° C. for 1 hour and then at 140 ° C. for 2 hours. Thereafter, xylene was added to this system to make the organopolysiloxane component 60% by weight to prepare a xylene solution of 350 poises of organopolysiloxane for silicone pressure-sensitive adhesive. Next, in 100 parts by weight of a xylene solution of this organopolysiloxane for a silicone-based pressure-sensitive adhesive, 20 centipoise of both ends of a molecular chain, a trimethylsiloxy group-blocked methylhydrogenpolysiloxane (content of silicon-bonded hydrogen atoms = 1.56) was added. % By weight), 0.2 parts by weight of 3-methyl-1-butyn-3-ol, and 50 parts by weight of toluene are mixed, and then 1,3-divinyl-1,1, platinum. 3,3-
A tetramethyldisiloxane complex is added in an amount such that the platinum metal in the complex is 100 ppm by weight unit with respect to the organopolysiloxane component, and the organopolysiloxane component is 40% by weight. An adhesive was prepared. Various properties of this pressure-sensitive adhesive were measured by the above methods, and the results are shown in Table 1.

Comparative Example 3 A raw rubber-like dimethylpolysiloxane having a plasticity of 142 in which 20 mol% of the terminal groups of the molecular chain are vinyl groups and the rest are hydroxyl groups bonded to silicon atoms (containing vinyl groups). Amount = 0.004% by weight) 27
Parts by weight and average unit formula: [(CH ₃ ) ₃ SiO _1/2 ] _0.7 (SiO _4/2 ) _1.0 represented by organopolysiloxane (containing 2.0% by weight of a hydroxyl group bonded to a silicon atom). 35 parts by weight were uniformly mixed with 40 parts by weight of xylene, and 0.5 part by weight of tributylamine (bp = 216 ° C.) was added to this system. The system was heated to 70 ° C. and stirred for 1 hour. After confirming that the partial condensation had proceeded, tributylamine was distilled off by heating and stirring at 140 ° C. for 2 hours while flowing nitrogen gas into the system. Then, xylene was added to this system to make the organopolysiloxane component 60% by weight to prepare a xylene solution of 420 poises of organopolysiloxane for silicone pressure-sensitive adhesive. next,
In 100 parts by weight of a xylene solution of this organopolysiloxane for a pressure-sensitive adhesive of silicone, methylhydrogenpolysiloxane with a molecular chain of 20 centipoise blocked at both ends of a trimethylsiloxy group (content of silicon-bonded hydrogen atoms =
1.56% by weight) 0.2 parts by weight, 0.2 parts by weight of 3-methyl-1-butyn-3-ol, and 50 parts by weight of toluene were mixed, and then 1,3-divinyl-1 of platinum was added thereto. ，
The 1,3,3-tetramethyldisiloxane complex is added in an amount such that the platinum metal in the complex is 100 ppm by weight with respect to the organopolysiloxane component,
A silicone-based pressure sensitive adhesive having an organopolysiloxane component of 40% by weight was prepared. Various properties of this pressure-sensitive adhesive were measured by the above methods, and the results are shown in Table 1.

[0032]

[Table 1]

[0033]

The silicone-based pressure-sensitive adhesive of the present invention is characterized by being cured by an addition reaction so that it can be satisfactorily adhered to a silicone rubber. Further, the organo-polysiloxane for a silicone-based pressure-sensitive adhesive of the present invention is also provided. Is characterized in that such a silicone-based pressure-sensitive adhesive can be prepared.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor ▲ Sai ▼ Takeaki Ki 2-2 Chikusaigan, Ichihara, Chiba Toray Dow Corning Silicone Co., Ltd.

Claims (2)

[Claims] 1. A raw rubber-like diorganopolysiloxane in which (a) 10 to 80 mol% of molecular chain terminal groups are alkenyl groups, and the rest are hydroxyl groups bonded to silicon atoms,
(b) An average unit formula containing an average of one or more hydroxyl groups or alkoxy groups bonded to silicon atoms in the molecule: (R ¹ ₃ SiO _1/2 ) _x (SiO _4/2 ) _1.0 (wherein R is ¹ is a substituted or unsubstituted monovalent hydrocarbon group, x is a number of 0.5 to 1.0), and (c) has a boiling point of -10 under normal pressure.
An organopolysiloxane for silicone pressure-sensitive adhesives, which is partially condensed with an amine compound having a temperature of up to 200 ° C. 2. A silicone-based organopolysiloxane for pressure-sensitive adhesives according to claim 1, and (B) an organopolysiloxane containing an average of two or more silicon-bonded hydrogen atoms in one molecule. {Amount of donating 0.7 moles or more of silicon atom-bonded hydrogen atoms to 1 mole of alkenyl group in component (A)}, and (C) platinum catalyst {based on organopolysiloxane component of the present composition The amount of platinum metal in the component (C) is 0.1 to 1000 ppm by weight}.